Melt infiltrated Tungsten-Copper composites as advanced heat sink materials for plasma facing components of future nuclear fusion devices

The exhaust of power and particles is regarded as a major challenge in view of the design of a magnetic confinement nuclear fusion demonstration power plant (DEMO). In such a reactor, highly loaded plasma facing components (PFCs), like the divertor vertical targets, have to withstand both severe high heat ux loads and considerable neutron irradiation. Existing divertor target designs make use of monolithic tungsten (W) and copper (Cu) material grades that are combined in a PFC. Such an approach, however, bears engineering difficulties as W and Cu are materials with inherently different thermomechanical properties and their optimum operating temperature windows do not overlap. Against this background, W-Cu composite materials are promising candidates regarding the application to the heat sink of highly loaded PFCs. The present contribution summarises recent results regarding the manufacturing and characterisation progress of such W-Cu composite materials produced by means of liquid Cu melt infiltration of open porous W preforms. On the one hand, this includes composites manufactured by infiltrating powder metallurgically produced W skeletons. On the other hand, W-Cu composites based on textile technologically produced fibrous reinforcement preforms are discussed

Beneficial Effects of a WC Addition in FAST-Densified Tungsten

The particle reinforcement of fusion-relevant tungsten through the incorporation of tungsten sub-carbide W2C particles at the grain boundaries is demonstrated as an effective way of eliminating the harmful W oxide, enhancing densification and stabilising the composite's microstructure and flexural strength at room and high temperatures. The W2C particles are formed in situ during the sintering by carbon diffusion from WC nanoparticles added as a precursor to the W matrix. Even in an extremely fast sintering process using Field-Assisted Sintering Technology (FAST, 1900 °C, 5 min), the added WC completely transforms to W2C, resulting in a W–W2C composite. While at least 5 vol % of WC nanoparticles are needed to eliminate the oxide, approximately 10 vol % result in a W–W2C composite with favourable characteristics: high density, high flexural strength at RT (>1200 MPa) as well as at elevated temperatures, and high thermal conductivity, which remains above 100 W/mK up to 1000 °C

Beneficial Effects of a WC Addition in FAST-Densified Tungsten

The particle reinforcement of fusion-relevant tungsten through the incorporation of tungsten sub-carbide W2C particles at the grain boundaries is demonstrated as an effective way of eliminating the harmful W oxide, enhancing densification and stabilising the composite's microstructure and flexural strength at room and high temperatures. The W2C particles are formed in situ during the sintering by carbon diffusion from WC nanoparticles added as a precursor to the W matrix. Even in an extremely fast sintering process using Field-Assisted Sintering Technology (FAST, 1900 °C, 5 min), the added WC completely transforms to W2C, resulting in a W–W2C composite. While at least 5 vol % of WC nanoparticles are needed to eliminate the oxide, approximately 10 vol % result in a W–W2C composite with favourable characteristics: high density, high flexural strength at RT (>1200 MPa) as well as at elevated temperatures, and high thermal conductivity, which remains above 100 W/mK up to 1000 °C

The Influence of Cyclic Thermal Shocks at High Temperatures on the Microstructure, Hardness and Thermal Diffusivity of the Rene 41 Alloy

The precipitation-hardenable nickel-based superalloy Rene 41 exhibits remarkable mechanical characteristics and high corrosion resistance at high temperatures, properties that allow it to be used in high-end applications. This research paper presents findings on the influence of thermal shocks on its microstructure, hardness, and thermal diffusivity at temperatures between 700 and 1000 °C. Solar energy was used for cyclic thermal shock tests. The samples were characterized using microhardness measurements, optical microscopic analysis, scanning electron microscopy coupled with EDS elemental chemical analysis, X-ray diffraction, and flash thermal diffusivity measurements. Structural transformations and the variation of properties were observed with an increase in the number of shocks applied at the same temperature and with temperature variation for the same number of thermal shocks

Palm-Plant Pain, Sign of a Severe Systemic Disease? Case Report and Review of Literature

Fabry disease is an X-linked lysosomal storage disease, second in prevalence after Gaucher disease. The onset of symptoms occurs in childhood or adolescence with palmo-plantar burning pains, hypo hidrosis, angiokeratomas, and corneal deposits. In the absence of diagnosis and treatment, the disease will progress to the late phase, characterized by progressive cardiac, cerebral and renal damage, and possible death. We present the case of an 11-year-old male boy who was transferred to the Pediatric Nephrology Department for palmo-plantar burning pain and end stage renal disease. Following the evaluations for the etiology of end stage renal disease we excluded the vasculitis, the neurologic diseases, extrapulmonary tuberculosis. Because of suggestive aspect at CT scan and lack of etiologic diagnosis of renal insufficiency we performed lymph node and kidney biopsy, with a surprising result for storage disease. The specific investigation confirmed the diagnosis